In the cotton industry, the normal method of banding or tying cotton bales has been to have workmen direct a tie, such as a band or wire, around a bale and then secure the ends of the ties appropriate depending on the design of the tie.
A manual-type bale-tying operation is described in U.S. Pat. No. 3,477,363 to Trumbo, the disclosure of which is expressly incorporated herein by reference.
Trumbo discloses that a bale, such as a bale of cotton, can be tied using a plurality of wires that have interlocking ends pre-formed into loops. In such a bale-tying operation, two workmen are normally (one on each side of the baling press) to manually bend the wires around the bale and to secure the ends of the wires together in a wire tie guide assembly. The wires are normally tied together sequentially, one at a time.
Since a plurality of wires are required to properly secure a cotton bale, e.g., a "universal density" cotton bale requires 8 wires, a manual-type bale-tying process can take a substantial amount of time. The amount of time it takes to tie a cotton bale is important since the process of pressing the next bale cannot begin until the preceding bale has been tied and removed from the press.
An automatic-type bale-tying apparatus is described in U.S. Pat. No. 4,484,510 to Jaenson, the disclosure of which is expressly incorporated herein by reference.
Jaenson discloses a hydraulically operated wire tying device for mounting on a baling press for tying a plurality of wires having pre-formed interlocking ends around a bale formed in a press. Pivotally mounted wire bend assemblies take the place of workmen on each side of the baling press for bending the tie wires around a bale and inserting the ends of the tie wires into a wire tie guide assembly.
A follow block, which is connected to and driven by the press ram below the bale, forms the floor of the baling chamber and includes a wire closer assembly. The wire bend assemblies pivot from a fully raised to a fully lowered position to bend the pre-formed interlocking ends of the wire around the bale and insert the interlocking ends into the wire closer assembly where the interlocking ends are joined together to form a knot.
Although an improvement over a manual-type bale-tying operation, Jaenson's hydraulically operated wire tying device still exhibits some problems which slow the ginning process. Exact timing is required for the sequence of events which makes up a wire tying operation. If a wire does not follow the correct path at the correct time, several factors can combine to prevent the interlocking ends of the wire from engaging in a knot. In particular, the interlocking ends of the wires are conventionally oriented such that the loops are disposed in a generally horizontal plane. This geometric orientation forces the wire closers to be constructed with relatively wide cavities, in order to accommodate the wide aspect ratios of the loops. This, in turn, allows the wires a greater degree of freedom of movement within the cavities. Consequently, there is a greater probability of one wire merely sliding past another, without their loops engaging in a knot.
In addition, press wear, both alone or in combination with component manufacturing tolerances, can cause the follow block to vary its position or orientation both vertically or from side to side. Consequently, the wire bend assemblies may not be in alignment with the wire tie guide assemblies. All the above-described cases result in mis-ties, with a consequent loss of time and possible damage to the press.
Recently, the very nature of the cotton ginning process has been changed due to the introduction of a down-packer type baling press, in which the press ram is disposed above a box full of cotton and compresses the bale by moving downward against a stationary base plate. Down-packers have been developed in response to a peculiar environmental factor found in all cotton growing regions throughout the world; namely, a water table extremely close to ground level. In the past, cotton balers were of necessity constructed with their baling chambers at ground level for easy accessibility. Buildings constructed to house conventional up-packer baling presses would often require a cofferdam to be built into the ground surrounding a basement chamber which housed the hydraulics of the baling press ram. Such structures are very expensive to build.
The down-packer baling press disposes the press ram and the hydraulics for operating the ram in a mezzanine space above the baling chamber, which remains at approximately a workman's waist level on the ground level of a ginning house. The floor of the baling chamber is stationary and a bale is compressed by downward motion of the press ram against the stationary floor of the chamber.
However, because of the particular orientation of a down-packer press, it is not possible to adapt an automatic wire tier designed for an up-packer type press to the structure of the down-packer. In particular, in a manner well understood by those having skill in the art, the floor of a baling chamber is best described as a rectangular plate centrally mounted on a pivot post and which extends to either side in cantilever fashion and functions in the manner of a turntable. Raw cotton is packed into a pressing box placed on one side of the turntable-like structure and, when the box is full, the turntable (the base plate) is rotated 180 degrees into position over a base frame and underneath the press ram. The other side of the turntable (the base plate) is now exposed so that a second baling box may be packed with raw cotton while the first is being compressed.
Since wires need to be tied around the bale, the base plate must include guide tubes and slots through which wires may be inserted prior to tying. After insertion, the wires are required to be in a suitable position for engagement with an automatic wire-tying device. The geometry of previous up-packer wire-tying devices precludes their use on down-packer type presses. Simple inversion of their location would be impossible because of the construction and operation of the turntable-like down-packer press base plate.
Accordingly, an apparatus (and process) for tying bales formed in a down-packer type baling press, that is designed for efficient, error free operation is needed. Such an apparatus should be designed for easy operation by one workman to reduce labor costs, while at the same time being easy to install or retro fit to existing presses.